Check out www.laserpcb.com
We make copper foils laminated to kapton that you can put through an unmodified laser printer and directly deposit the toner onto the copper. The laminate has a pressure-sensitive adhesive to allow you to stick it to the supplied FR4 board before etching.
Dave
--- In Homebrew_PCBs@yahoogroups.com, Mark Lerman <mlerman@...> wrote:
>
> For anyone interested, there is absolutely no reason that laser
> printers cannot directly deposit toner on pcb boards. The practical
> problems are the fuser and the paper path. As a proof of concept, I
> took a Brother HL2140 laser printer that has a manual feed for
> thicker media and fed a sheet of thin (8 mil) laminate through the
> printer. Nothing printed.
>
> I then removed the fuser, using appropriate resistors to simulate the
> correct fuser temperature and thereby fool the printer controller
> into thinking the fuser was still there. I ran the same test, and
> sure enough, it printed perfectly! Of course, the toner was only held
> to the board by electrostatic attraction, but I then put the board
> into my trusty toaster oven and "fused" it.
>
> There are other practical problems, but these can be overcome with a
> little bit of work. A small mcu will be needed to simulate some of
> the feed sensors and the paper path will have to be changed, but my
> experiments show that these are (relatively) easily done.
>
> I have used a datalogger to check the function of the three main
> sensors - paper feed, start print (rear register) and eject - and can
> simulate all of these and I have actually run the printer using an
> mcu instead of the sensors. However, the real problem is that the
> machine is not rugged enough to handle a lot of manipulation - the
> connectors break down easily and you end up with error lights that
> you have no idea how to fix, a tiny slip that causes a momentary
> short will sometimes blow a board, etc.
>
> If anyone is interested in more details, I am happy to share.
>
> Mark
>